“CAPTCHA”, which is trademarked the Carnegie Mellon University, is a short form for “Completely Automated Public Turing test to tell Computers and Humans Apart”. It is a test, which helps the computer to differentiate between machines and human beings. It has the capability of creating and grading tests that automatically accepts all humans and rejects all machines.
It gives you a test to decipher distorted numbers and letters, which are pretty easy for a person to do, but cannot be figured out by a machine. For further details about CAPTCHA and smart CAPTCHA go to http://www.protectwebform.com/ and http://www.protectwebform.com/smartcaptcha.
Having a CAPTCHA installed can protect against bots, which are programs that can repeatedly spam inboxes, try to post and retrieve personal information in chatrooms, and also try to get e-mail addresses and other information to use for promotions to sell services or items, or sign you up for numerous free mail services.
The bots crack your passwords, encroach upon your privacy and use your personal information for commercial use without your permission. They create worms that can cause immense harm to your machine.
You can use a CAPTCHAS or a CAPTCHA plug-in (http://www.protectwebform.com/plugin_wordpress) to stop these bots from taking over your system. Many sites of all sizes have installed these. Once the CAPTCHA is running as bots try to get into your system, they will be asked to type out a distorted image shown on the screen. Since computers can rarely translate these messy images into letters as humans can, it can stop the bot. you may have seen a CAPTCHA when logging onto your mail service, into a chatroom, or onto your bank website.
Spam seems to unfortunately be way of life. Day in and day out spammers are sending message after message into your e-mail system. But it’s not just in e-mail that you may be hit with spam. Spam also is a problem in online newsgroups, logs, search engines and even instant messaging!
Advertisers resort to spamming as spamming does not incur any kind of operating costs other than the cost of managing the list of individuals that are targeted to receive the mails. Also you cannot hold the sender accountable for the mass mailers they send. Since there is no entry barriers, spamming has become really ubiquitous. This is the reason why all your inbox is so inundated with mass mailers whenever you access them.
Usenet spam is a message that can be sent to twenty or more Usenet newsgroups. This kind of spam floods the newsgroups with unnecessary advertisement and posts. It also challenges your ability to accept and manage the topics on the system.
Another kind of spam, which is a little more expensive, is the instant message spam. In this case, advertisers have paid a little more to get a hold of a list of instant messaging ID’s and then sent messages directly to those people.
